OBJECTIVES: The Open-Source Value Project (OSVP) promotes and facilitates an open-source, collaborative, and iterative approach to cost-effectiveness model development. We are presenting the next OSVP model, which can be used to estimate the value of alternative sequential treatment strategies (1L -> 2L -> 2L+) for metastatic EGFR+ non-small cell lung cancer (NSCLC).

METHODS: The flexible open-source simulation model, accessible to both technical and non-technical end-users, enables a more constructive dialogue between stakeholders (e.g. patients, payers, providers, and manufacturers) with different beliefs about relevant clinical data, modeling approaches, and value perspective. To facilitate transparency, debate and collaboration among diverse stakeholders, the model consists of the following components: Modifiable R and C++ source code available in a GitHub repository; an R-package to run the model for custom analyses; a web-based user interface for full control over the model without the need to be well-versed in the programming language; and a general audience web-application allowing those who are not experts in modeling or health economics to interact with the model, and contribute to the discussion of value assessment. Model input parameters were estimated based on currently available evidence, synthesized with Bayesian meta-analysis techniques.

RESULTS: The model was used to evaluate the impact of uncertainty in clinical evidence, multiple competing model structures, decision framework of choice (i.e. cost-effectiveness analysis or multi-criteria decision analysis), and perspective (healthcare or limited societal) on estimates of value for currently recommended treatment sequences for patients with metastatic EGFR+ NSCLC.

CONCLUSIONS: In order for a cost-effectiveness model to remain relevant over time it needs to evolve along with the clinical evidence and scientific insights. The OSVP EGFR+ NSCLC facilitates iterative development and collaboration between multiple clinical and methodological experts with the ultimate aim of having a transparent model useful and acceptable for many stakeholders.